The present invention relates to local warning systems and, more particularly, to automatic warning systems for use with portable radiation emitting devices.
Safety regulations governing the use of radiation emitting devices, such as class 3b and 4 lasers, typically require that a warning, sign be placed outside the door of any room in which a laser is being used. The warning sign may be removed when the emitting device is not in use to reduce the risk that the sign may be ignored. A technician may place a passive (e.g., unlit) sign on the door when the device is in use, but such a device may not draw sufficient attention to be noticed at all times. The technician may leave the sign in place continuously, which can increase the risk that the sign may be ignored. Technicians may also forget to place the sign on the door at all, leading to non-compliance with safety regulations and increased liability.
Active warning systems for laser use are available and typically use a hardwired connection from the laser to a sign on an access door to the room or enclosure in which the laser is used. When the laser is on, the warning sign on the door is illuminated. These systems may incorporate locks for the door and beam interrupters for the laser that activate if the door is open. These systems can require significant installation preparation, particularly when the laser is relocated. Mobile or semi-mobile radiation emitting devices may be disconnected and reconnected to a warning system when they are moved from one room to another. This process can be cumbersome and can increase laser operator or set-up errors.